Japan's confirmed daily coronavirus cases on Sunday topped 20,000 for the third consecutive day, as the country continues to battle with the rapid spread of the Omicron variant.

The tally comes a day after new infections nationwide almost reached the record high number of 25,992 registered on Aug. 20 last year, when the country was reeling from the worst of the fifth wave of infections.

People wearing face masks for protection against the coronavirus walk in Tokyo's Ginza area on Jan. 16, 2022. (Kyodo)

Cases have surged about 50-fold in the last two weeks, with some prefectures across Japan continuing to report record numbers of infections.

On Sunday, Osaka logged a record 3,760 new cases while Hiroshima updated its all-time high for the fourth day in row at 1,280 cases.

Tokyo confirmed over 4,000 new cases for the third consecutive day at 4,172, while Okinawa saw 1,226 cases.

Japan on Saturday marked two years since its first COVID-19 case was confirmed, and what appeared to be the first Omicron death reported in the country. To date, the cumulative number of cases has reached more than 1.8 million, with the death toll exceeding 18,000.

Based on studies suggesting the Omicron variant has a shorter incubation period and causes less severe illness than previous mutations of the virus, Japan from Saturday shortened the quarantine period for all overseas entries from the current 14 days to 10.

The decision followed a similar shortening of the isolation period for close contacts of the new variant among the general public from 14 days to 10, and for essential workers to a minimum of six days.

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